1. Field of the Invention
The present invention relates to a plasma display panel (PDP) driver and a method thereof, and more particularly, to an apparatus for driving a PDP, which is capable of increasing an energy recovery rate and simplifying the structure of a sustain circuit, and a method thereof. The present application is based on Korean Patent Application No. 2001-35761, filed Jun. 22, 2001, which is incorporated herein by reference.
2. Description of the Related Art
In general, a plasma display panel (PDP) is a next-generation flat display which displays text or images with the use of plasma generated by gas discharge, and is comprised of several hundreds of thousands of pixels or several millions or more of pixels arranged in a matrix type. Here, the number of pixels included in a PDP is dependent on the size of the PDP.
FIG. 1 is a diagram illustrating a conventional PDP driver. In the prior art, switching operations for displaying images on a PDP are determined based on an address display separation (ADS) method. Referring to FIG. 1, switches Ys, Yg, Xs, and Xg are sustain switches for applying a high-frequency alternating current (AC) pulsed voltage to a PDP in the sustain period of the PDP. During the sustain period of the PDP, two pairs of switches (Ys, Xg) and (Xs, Yg) alternate in being turned on and off. Other switches Yr, Yf, Xr, and Xf are switches of an energy recovery circuit for controlling power consumption by preventing the voltage and capacitive displacement current of a PDP from rapidly varying. Reference characters LY and LX represent inductors for energy recovery, capacitors C_Yerc and C_Xerc and diodes D_Yr, D_Xf, D_Xr, D_Xf, D_YvsC, D_YGC are necessary to constitute a conventional energy recovery circuit, which has been suggested by Weber, et al. In general, a network including sustain switches, energy recovery switches, and passive devices is referred to as a xe2x80x9csustainxe2x80x9d circuit. In an ADS method, the sustain circuit operates only in the sustain period of a PDP. A switch Yp is for separating circuitry operated in the sustain period of the PDP from circuitry operated in other periods (an address period and a reset period) of the PDP in the ADS method. Switches Yrr, Yfr, and Xrr are for applying a ramp-type high voltage to the PDP during the reset period of the PDP and apply a voltage higher than power supply voltage to the PDP during the reset period of the PDP, operating with capacitors Cset and C_Xsink. Switches Ysc and Ysp operate in the address period of the PDP in the ADS method. Specifically, in the address period of the PDP, Ysp is turned on, but Ysc is turned off. On the other hand, in other periods of the PDP, Ysp is turned off, but Ysc is turned on. A scan driver integrated circuit 100 which is comprised of shift register and voltage buffers operates to apply a horizontal synchronization signal of a PDP screen in the address period of the PDP and is short-circuited in other periods. Details of the structure and operation of the conventional PDP driver based on the order of switching operations are set forth in U.S. Pat. No. 4,866,349.
In the conventional PDP driver, the conventional sustain circuit, which directly affects the illumination and power consumption of a PDP, requires many switch devices and passive devices. In addition, since the conventional sustain circuit takes advantage of a pure LC resonance phenomenon when charging and discharging a PDP, the PDP is rapidly charged or discharged all the time in a case where parasitic resistance of the PDP exists, and switching loss occurs at a MOS field effect transistor (MOSFET) switch. Accordingly, the power efficiency of the sustain circuit decreases, and the EMI of the sustain circuit increases. In addition, capacitive displacement current increases, and then displacement power and device stress also increase. Thus, illumination efficiency decreases.
To solve the above-described problems, it is an object of the present invention to provide a plasma display panel (PDP) driver, which has a decreased number of devices and is capable of increasing an energy recovery rate for reducing displacement power, and a method thereof.
Accordingly, to achieve the above object, there is provided an apparatus for driving a plasma panel display (PDP), which is capable of improving an energy recovery rate, the apparatus for driving a PDP comprising an energy recovery circuit and a plurality of switches, wherein the energy recovery circuit comprises a switch for applying a power source during a gas discharging period of the PDP; capacitors connected in series between the power source and ground; and an inductor connected between a point in a path connecting the two capacitors and an output terminal of the switch, whereby a switching sequence is set for controlling turning on/off of the switch and the plurality of switches so that the maximum instantaneous current of the inductor can flow into the PDP at a transition time between charging of the PDP and discharging of the PDP.
To achieve the above object, there is provided a method for driving a PDP, which has an energy recovery circuit including an inductor for recovering power when charging/discharging the PDP in the sustain period and exhibits a switching sequence of repeatedly performing a reset period, an address period, and a sustain period, the method for driving a PDP controls the switching sequence so that the maximum instantaneous current of the inductor of the energy recovery circuit can flow into the PDP at a transition time between charging of the PDP and discharging of the PDP in the sustain period.